Transformer tank structure



June 21, 13. L. BROWN 2,121,533

TRAN$FORMER TANK STRUCTURE Filed Feb. 8, 1935 INVENTOR Patented June 21 1938 UNITED f STATES PATENT OFFl C TRANSFORMER, TANK STRUCTURE Roy L. Brown, Sharon, Pa", assignor to 'West- I mghouse Electric .& Manufacturing. Company,

East Pittsburgh, Pa,

syivania a corporation of Penn- Application February 8, 1935, Serial No. 5,572

4 Claims.

This invention relates to transformer cases and is particularly adapted for use in transformer cases in which it is desired to have an oil or gas-tight point between the cover and the case or between the different sections of the case where the transformer case is sectionalized.

An object of this invention is the provision of a simple and eificient joint construction which is adapted to provide leak-proof joints in cases for electrical apparatus.

The invention, together with additional objects and advantages thereof will be better understood from'the following description when read in conjunction with the accompanying drawing, in which:

Figure l is a view, partly in elevation and partly in section, showing an oil immersed trans: former in a case, the joints of which embody the features of this invention;

Fig. 2 is a vertical sectional'view showing a joint between a cover and a case and embodying the features of this invention;

Fig. 3 is a vertical sectional view illustrating this invention as embodied in a joint between the upper and lower sections of a sectionalized. case; and

Fig. 4 is a vertical sectional view showing a joint between the cover and a case asembodied in a modification of this invention.

Like reference characters indicate similar parts in the diiferent figures of the drawing.

Referring to the drawing and particularly to Fig. 1, this invention is illustrated with reference to a sectionalized transformer case In comprising an upper section II and a lower section l2. The case 10 contains oil id or other suitable insulating medium in which transformer i3 is immersed. A cover I5 is positioned on the case I 0 as will hereinafter be described. As is usual in oil immersed transformers, the case I0 is large enough to contain the oil necessary for the cooling of the transformer l3, the transformer leads l6, and the bushings H.

In an embodiment of this invention illustrated in Fig. 1 and particularly in the vertical sectional view shown in Fig. 3 as applied to the sectionalized case, a flanged ring or stop I8 is provided near the upper edge of the inner wall of the lower section 12 in order to provide a rest or stop for supporting the upper section H in its position relative to the lower section l2. The flanged ring I8 is securely welded as at H) to the lower section I2 to provide a mechanically strong stop for withstanding the weight of upper portion H and to support it in assembled position.

Guides are provided adjacent the stop and in spaced relation around the inner wall of the lower section l2 for guiding the upper section I! into assembled position with its lower edge abutting the flanged ring l8.

For test purposes and before the joint is flnally completed, a gasket 2| may be provided between the lower edge of the upper section II and'the flanged ring it, although, as will be evident from the following description, such a gasket may be 1-0 discarded in the flnal assembled structure.

The upper and lower sections of the case are provided with loops 22 which are adapted to receive bolts 23 for securing the sections of the case together. The loops and bolts are so spaced it around the case as to hold the mechanical stresses encountered in lifting and positioning the completed structure.

In order to provide a leak-proof joint between the upper and lower sections of the case when finally assembled, a thin metal band 24 which overlaps the upper and lower sections of the case is securely welded along its lower edge 25 to and around the outer wall along the upper edge of the lower section i2. When the transformer is installed and the upper section II is positioned on the stop I8, the upper portion of the metal band 24 is bent by some suitable means, into contact with the upper section. II and se curely welded thereto along its upper edge by a weld 26. Such a welding of thefmetal band 24 along its upper and lower edges to the" upper and lower sections of the case provides a leakproof joint between the upper and lower sections of the sectionalized case. The thin metal band 24 is sufficiently flexible to permit slight relative lateral movements of the transformer case sections without any appreciable stress on the welds.

As illustrated in Figs. 1 and 2, this type of joint is also suitable for maintaining the cover i5 in leak-proof engagement with the case I0. In such a construction, the cover l5 projects beyond the case and is provided with openings 21 so spaced in relation to the loops 22 as to receive the bolts 23. The cover is securely welded, as at 28, to the section 29 of the case 10 which rests on the flanged ring l8 welded to the section II of the transformer case.

As hereinbefore described, in order to provide 0 a leak-proof joint, a thin metal band 24 which overlaps the sections of the case forming the joint, is welded along its upper and lower edges to the upper and lower sections of the case while only a sufficient number of bolts 23 are employed to compensate for the mechanical stresses encountered.

A modification of this invention is illustrated in Fig. 4 as applied to a transformer case in which it is undesirable or unnecessary to employ bolts for compensating for the mechanical stresses. In this modification, the flanged ring or stop I8 is securely welded to and around the outer wall of the case, while the section 29, upon which the cover I5 is mounted, is of such a size as to provide a close fitted lap joint with the section H and to be positioned on the stop I8. The thin metal band 24 is mounted on and welded to the stop 18 along its lower edge 25. When the upper portion of the metal band 24 is bent into contact with the section 29 of the case, it is securely welded thereto, as by a weld 26, along its upper edge and effects a leak-proof joint between the section 29 of the case and the stop III.

In practice, where it is necessary to enter the transformer to make repairs, this joint may be out along the upper'weld 26. After the repairs have been made to the transformer, the case structure is easily reassembled without the addition of new parts. In order to reseal the structure it is only necessary to reweld the metal band 24 along the out weld, again effecting a leak-proof joint.

In practice, the thin metal band when positioned and sealed as hereinbefore described provides a welded leak-proof joint. Where such a joint is employed, it has been discovered that the number of bolts heretofore employed for positioning and holding the sections together may be materially reduced, only about one-fourth of the number heretofore employed being required tocompensate for the mechanical stresses encountered.

It is, of course, to be understood that, although this invention has been shown and described with reference to certain specific embodiments thereof,

many modifications are possible, and, it is, therefore, not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. In a transformer tank structure, a case, the case comprising upper and lower sections having a joint therebetween, a stop carried by the lower section for receiving the upper section, a metal band of substantial Width covering the joint between the upper and lower case sections and welded adjacent the upper and lower margins thereof to the case sections for sealing the joint, the metal band being sufficiently flexible to permit slight relative lateral movements of the upper and lower case sections when welded thereto.

2. In a transformer tank structure, a case, the case comprising upper and lower sections having a joint therebetween, a stop carried by the lower section for receiving the upper section, a metal band of substantial width disposed outside of the case sections and covering the joint between the upper and lower case sections, the metal band having an upper and lower edge, the lower edge of the metal band being welded to the lower case section, and the upper edge of the metal band being forced into contact with the upper case section and welded thereto to seal the joint between the case sections, the metal band being sufiiciently flexible to permit slight relative lateral movements of the upper and lower case sections when welded thereto.

3. In a transformer tank structure, a case, the case comprising upper and lower sections which overlap to form a joint, a stop carried by and disposed around the inside and near the upper edge of the lower case section for receiving the upper case section, a metal band of substantial width disposed around the outside of the case overlapping the upper and lower case sections, the metal band being welded adjacent the upper and lower margins thereof to the upper and lower case sections respectively to seal the joint therebetween, the metal band being sufliciently flexible to permit slight relative lateral movements of the upper and lower case sections when welded thereto.

4. In a transformer tank structure, a case, the case comprising upper and lower sections which overlap to form a joint, a stop carried by and disposed around the outside of the lower case section for receiving the upper case section, a metal band of substantial width disposed around the outside of the case overlapping the upper case section and the stop disposed on the lower case section, the metal band being welded adjacent the upper and lower margins thereof to the upper case section and the stop respectively to seal the joint, the metal band being sufficiently flexible to permit slight relative lateral movements of the upper and lower case sections when welded thereto;

ROY L. BROWN. 

